Pond Evaporation Calculation 1/31/17
Weather Station Data provided by Northern Colorado Water Conservancy District
See Weather Station Location Map at:
http://www.northernwater.org/WaterConservation/WeatherandETData.aspx
Notes:
Current month reflects values through "Reference Date".
Pond Evap. calculated per recent Division 1 Water Court decree language: Lower South Platte Home Page
Gross Pond = .84(Alfalfa ETr) Pond Evaporation Reports Main Menu
Net Pond = .84(Alfalfa ETr) - .7(Total Precip)
Alfalfa reference ETr computed by Standard ASCE equation from daily weather data.
Winter pond evap. is a reference for unfrozen ponds.
For Growing Degree Days:
Tmax = 86 F, Tmin = 50 F and Tbase = 50 F
Totals
Weather Station 2016 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec or Avg.
Ovid Avg. Temp F 26.58 35.16 42.47 48.62 55.71 73.8 74.59 70.25 62.91 54.06 41.31 24.21 50.81
Ref date as of 12/31/2016 Total Precip " 0.3 0.82 1.41 4.06 2.89 3.27 2.87 0.87 0.42 0.91 0.28 0.3 18.4
Site Type: Alfalfa Total Alfalfa ETr " 1.43 3.1 5.63 5.77 6.7 10.73 9.71 7.71 6.28 5.04 3.12 1.93 67.15
Total Growing Degee Days from March 1 0 0 177 199 300 642 695 601 462 364 169 11 3620
Gross Pond Evap Total " 1.2 2.6 4.73 4.85 5.63 9.01 8.16 6.48 5.28 4.23 2.62 1.62 56.41
Net Pond Evap Total " 0.99 2.03 3.74 2 3.61 6.72 6.15 5.87 4.98 3.6 2.42 1.41 43.52
Crook Avg. Temp F 26.1 35.99 42.85 48.83 55.55 72.66 74.02 69.52 62.71 53.61 40.61 23.56 50.5
Ref date as of 12/31/2016 Total Precip " 0.29 0.47 0.82 2.8 2.07 1.36 2.16 0.39 0.66 0.72 0.19 0.36 12.29
Site Type: Alfalfa Total Alfalfa ETr " 1.47 3.28 5.8 5.87 6.58 9.66 9.15 7.54 6.14 4.91 3.16 1.89 65.45
Total Growing Degee Days from March 1 0 0 182 207 299 614 684 573 470 377 178 17 3601
Gross Pond Evap Inch 1.23 2.76 4.87 4.93 5.53 8.11 7.69 6.33 5.16 4.12 2.65 1.59 54.97
Net Pond Evap Inch 1.03 2.43 4.3 2.97 4.08 7.16 6.17 6.06 4.7 3.62 2.52 1.34 46.38
 
Sterling Avg. Temp F 25.36 35.39 42.67 48.87 55.59 72.72 74.02 69.78 62.95 53.68 40.66 23.24 50.41
Ref date as of 12/31/2016 Total Precip " 0.22 0.53 0.63 3.29 2.62 1.41 1.67 0.53 0.95 0.43 0.35 0.43 13.06
Site Type: Alfalfa Total Alfalfa ETr " 1.4 3.18 5.51 5.8 6.45 9.69 9.15 7.74 6.18 4.78 2.98 1.57 64.43
Total Growing Degee Days from March 1 0 0 174 205 301 616 679 584 472 375 185 13 3604
Gross Pond Evap Inch 1.18 2.67 4.63 4.87 5.42 8.14 7.69 6.5 5.19 4.02 2.5 1.32 54.13
Net Pond Evap Inch 1.02 2.3 4.19 2.57 3.58 7.15 6.52 6.13 4.53 3.71 2.26 1.02 44.98
 
Brush Avg. Temp F 24.32 33.94 42.14 48.27 55.55 71.39 72.88 68.42 62.3 53.25 40.21 21.33 49.5
Ref date as of 12/31/2016 Total Precip " 0.28 1.16 1.79 3.51 3.23 1.33 3 1.5 0.68 0.54 0.3 0.74 18.06
Site Type: Alfalfa Total Alfalfa ETr " 1.31 3.02 5.45 5.84 6.69 9.08 9.18 7.54 6.2 5.01 3.15 1.37 63.84
Total Growing Degee Days from March 1 0 0 173 218 324 593 668 573 471 398 196 10 3624
Gross Pond Evap Inch 1.1 2.54 4.58 4.91 5.62 7.63 7.71 6.33 5.21 4.21 2.65 1.15 53.64
Net Pond Evap Inch 0.9 1.72 3.33 2.45 3.36 6.7 5.61 5.28 4.73 3.83 2.44 0.63 40.98
 
Fort Morgan Avg. Temp F 24.43 34.18 42.05 48.54 55.76 72.09 73.76 69.49 63.45 54.51 41.79 22.68 50.23
Ref date as of 12/31/2016 Total Precip " 0.16 0.48 2.4 3.46 3.44 2 5.63 2.46 1.8 0.67 0.62 0.67 23.79
Site Type: Turf Total Alfalfa ETr " 1.28 2.68 4.54 5.18 6.35 8.66 8.61 7.21 5.71 4.29 2.69 1.16 58.36
Total Growing Degee Days from March 1 0 0 159 209 314 604 682 595 492 392 183 10 3640
Gross Pond Evap Inch 1.08 2.25 3.81 4.35 5.33 7.27 7.23 6.06 4.8 3.6 2.26 0.97 49.01
Net Pond Evap Inch 0.96 1.92 2.13 1.93 2.93 5.87 3.29 4.33 3.54 3.13 1.83 0.51 32.37
 
Wiggins Avg. Temp F 22.72 33.71 41.64 48.13 54.93 71.44 72.78 68.87 62.5 53.41 40.56 21.65 49.36
Ref date as of 12/31/2016 Total Precip " 0.24 0.35 0.98 2.73 3.3 1.23 1.9 1.31 0.13 0.68 0.7 0.62 14.17
Site Type: Alfalfa Total Alfalfa ETr " 1.25 3.03 5.13 5.76 6.27 9.27 9.78 8.53 6.46 5.01 3.17 1.26 64.92
Total Growing Degee Days from March 1 0 0 157 212 302 590 656 576 472 373 178 6 3522
Gross Pond Evap Inch 1.05 2.55 4.31 4.84 5.27 7.79 8.22 7.17 5.43 4.21 2.66 1.06 54.56
Net Pond Evap Inch 0.88 2.3 3.62 2.93 2.96 6.93 6.89 6.25 5.34 3.73 2.17 0.62 44.62
 
Fort Collins East Avg. Temp F 27.64 36.01 41.21 47.03 52.61 69.94 71.68 67.07 61.5 53.23 42.02 24.51 49.54
Ref date as of 12/31/2016 Total Precip " 0.42 0.64 1.38 2.08 1.9 0.17 0.19 0.51 0.13 0.34 0.28 0.4 8.44
Site Type: Alfalfa Total Alfalfa ETr " 1.83 3.47 4.81 5.35 6.02 9.34 9.16 7.93 5.83 5.12 3.38 1.51 63.75
Total Growing Degee Days from March 1 0 0 124 178 257 561 630 535 439 341 172 10 3247
Gross Pond Evap Inch 1.54 2.91 4.04 4.49 5.06 7.85 7.69 6.66 4.9 4.3 2.84 1.27 53.55
Net Pond Evap Inch 1.24 2.47 3.07 3.04 3.73 7.73 7.56 6.3 4.81 4.06 2.64 0.99 47.64
 
Eaton Avg. Temp F 25.54 35.2 40.79 47.51 53.7 70.66 71.83 66.97 61.37 52.3 40.54 22.43 49.07
Ref date as of 12/31/2016 Total Precip " 0.51 0.53 1.65 2.51 2.99 1.3 0.49 0.77 0.43 0.83 0.36 0.65 13.02
Site Type: Alfalfa Total Alfalfa ETr " 1.57 3.35 4.95 5.65 6.44 9.39 8.74 7.31 5.53 4.46 3.06 1.24 61.69
Total Growing Degee Days from March 1 0 0 129 201 284 570 642 545 443 335 166 2 3317
Gross Pond Evap Inch 1.32 2.81 4.16 4.75 5.41 7.89 7.34 6.14 4.65 3.75 2.57 1.04 51.83
Net Pond Evap Inch 0.96 2.44 3 2.99 3.32 6.98 7 5.6 4.34 3.17 2.32 0.59 42.71
 
Johnsons Corner Avg. Temp F 26.94 35.5 41.16 47.46 53.35 70.65 73.33 68.44 63.23 54.72 43.27 24.78 50.24
Ref date as of 12/31/2016 Total Precip " 0.74 0.89 1.75 2.04 2.51 0.34 1.47 0.39 0.24 0.69 0.33 0.54 11.93
Site Type: Alfalfa Total Alfalfa ETr " 1.55 3.22 4.52 5.2 5.87 9.17 9.87 8 6.1 5.06 3.18 1.47 63.21
Total Growing Degee Days from March 1 0 0 115 185 258 573 668 559 460 352 175 14 3359
Gross Pond Evap Inch 1.3 2.7 3.8 4.37 4.93 7.7 8.29 6.72 5.12 4.25 2.67 1.23 53.08
Net Pond Evap Inch 0.78 2.08 2.57 2.94 3.17 7.46 7.26 6.45 4.96 3.77 2.44 0.86 44.74
 
Gilcrest Avg. Temp F 23.55 34.04 41.51 48.03 54.65 72.8 74.72 68.06 61.61 52.22 40.1 21.29 49.38
Ref date as of 12/31/2016 Total Precip " 0.49 0.52 0.82 2.75 2.35 1.2 2.25 1.67 0.8 0.7 0.33 0.4 14.28
Site Type: Alfalfa Total Alfalfa ETr " 1.3 3 4.56 5.43 6.26 9.47 9.27 7.36 5.53 4.46 2.67 1.25 60.56
Total Growing Degee Days from March 1 0 0 142 210 290 612 684 565 451 346 168 4 3472
Gross Pond Evap Inch 1.09 2.52 3.83 4.56 5.26 7.95 7.79 6.18 4.65 3.75 2.24 1.05 50.87
Net Pond Evap Inch 0.75 2.16 3.26 2.64 3.61 7.11 6.21 5.01 4.09 3.26 2.01 0.77 40.88
 
Longmont South Avg. Temp F 28.81 37.85 41.53 48.35 54.08 70.93 73.45 68.02 62.33 55.54 43.64 27.14 50.97
Ref date as of 12/31/2016 Total Precip " 0.48 0.77 1.63 2.18 1.3 0.99 0.8 0.72 0.4 0.44 0.31 0.57 10.59
Site Type: Alfalfa Total Alfalfa ETr " 1.78 3.69 4.39 5.37 5.76 8.87 9.44 7.41 5.75 5.58 3.04 1.85 62.93
Total Growing Degee Days from March 1 0 0 118 188 270 567 651 542 437 358 180 33 3344
Gross Pond Evap Inch 1.5 3.1 3.69 4.51 4.84 7.45 7.93 6.22 4.83 4.69 2.55 1.55 52.86
Net Pond Evap Inch 1.16 2.56 2.55 2.98 3.93 6.76 7.37 5.72 4.55 4.38 2.34 1.16 45.46
 
Fort Collins NW Avg. Temp F #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Ref date as of 12/31/2010 Total Precip " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Site Type: Turf Total Alfalfa ETr " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Total Growing Degee Days from March 1 0 0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Gross Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Net Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
 
Fort Collins Central Avg. Temp F 28.02 35.78 42.08 48.98 54.72 71.12 73.23 67.88 61.83 52.62 41.98 25.18 50.29
Ref date as of 12/31/2016 Total Precip " 0.62 0.21 1.37 2.56 1.88 0.15 1.09 0.7 0.21 0.4 0.29 0.29 9.77
Site Type: Turf Total Alfalfa ETr " 1.68 3.01 3.96 4.76 5.48 7.47 7.72 6.44 4.74 3.68 2.45 1.24 52.63
Total Growing Degee Days from March 1 0 0 129 201 290 574 656 546 445 341 173 9 3364
Gross Pond Evap Inch 1.41 2.53 3.33 4 4.6 6.27 6.48 5.41 3.98 3.09 2.06 1.04 44.2
Net Pond Evap Inch 0.98 2.38 2.37 2.21 3.29 6.17 5.72 4.92 3.83 2.81 1.86 0.84 37.38
 
Windsor Avg. Temp F #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Ref date as of 7/1/2012 Total Precip " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Site Type: Dryland Pasture Total Alfalfa ETr " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Total Growing Degee Days from March 1 0 0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Gross Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Net Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
 
Greeley West Avg. Temp F 25.73 35.11 41.48 48.1 54.75 71.8 74.15 68.98 63.22 53.85 41.93 22.84 50.16
Ref date as of 12/31/2016 Total Precip " 0.62 0.64 1.12 2.56 2.31 1.53 0.97 1.26 0.27 0.79 0.36 0.78 13.21
Site Type: Turf Total Alfalfa ETr " 1.36 2.83 4.3 4.97 6.07 8.37 8.25 6.83 5.16 3.95 2.52 1.17 55.78
Total Growing Degee Days from March 1 0 0 135 219 296 606 684 584 474 361 176 8 3543
Gross Pond Evap Inch 1.14 2.38 3.61 4.17 5.1 7.03 6.93 5.74 4.33 3.32 2.12 0.98 46.85
Net Pond Evap Inch 0.71 1.93 2.83 2.38 3.48 5.96 6.25 4.86 4.15 2.77 1.86 0.44 37.62
 
Loveland Avg. Temp F 28.68 36.75 41.89 48.67 55.05 71.8 74.39 69.31 63.91 55.53 43.79 26.9 51.39
Ref date as of 12/31/2016 Total Precip " 0.46 0.42 1.5 1.82 2.04 0.42 0.88 0.4 0.27 0.4 0.21 0.39 9.21
Site Type: Turf Total Alfalfa ETr " 1.67 3.01 4.1 4.88 5.67 8.07 8.72 6.66 5.08 4.26 2.6 1.53 56.25
Total Growing Degee Days from March 1 0 0 137 221 308 614 693 595 509 406 219 30 3732
Gross Pond Evap Inch 1.4 2.53 3.44 4.1 4.76 6.78 7.32 5.59 4.27 3.58 2.18 1.29 47.24
Net Pond Evap Inch 1.08 2.23 2.39 2.83 3.33 6.48 6.71 5.31 4.08 3.3 2.04 1.01 40.79
 
Berthoud Avg. Temp F 28.7 36.95 41.85 48.41 54.41 71.53 74.2 68.94 63.77 55.59 44.24 25.75 51.2
Ref date as of 12/31/2016 Total Precip " 0.58 0.94 1.89 1.8 1.95 0.26 0.26 1.4 0.15 0.4 0.18 0.5 10.31
Site Type: Turf Total Alfalfa ETr " 1.58 3.12 4.29 4.99 5.86 8.63 9.05 7.06 5.37 4.77 2.9 1.46 59.08
Total Growing Degee Days from March 1 0 0 121 197 271 611 697 580 465 354 173 16 3485
Gross Pond Evap Inch 1.33 2.62 3.6 4.19 4.92 7.25 7.6 5.93 4.51 4.01 2.44 1.23 49.63
Net Pond Evap Inch 0.92 1.96 2.28 2.93 3.56 7.07 7.42 4.95 4.41 3.73 2.31 0.88 42.42
 
Longmont West Avg. Temp F 29.15 37.65 41.73 48.81 54.73 71.75 74.57 69.2 63.37 56.16 43.64 27.75 51.54
Ref date as of 12/31/2016 Total Precip " 0.42 0.51 1.72 1.77 2.1 0.6 0.09 0.79 0.3 0.37 0.15 0.25 9.07
Site Type: Turf Total Alfalfa ETr " 1.49 2.81 3.6 4.59 5.42 7.59 8.09 6.38 4.9 4.33 2.35 1.47 53.02
Total Growing Degee Days from March 1 0 0 117 187 267 594 694 579 458 366 181 36 3479
Gross Pond Evap Inch 1.25 2.36 3.02 3.86 4.55 6.38 6.8 5.36 4.12 3.64 1.97 1.23 44.54
Net Pond Evap Inch 0.96 2 1.82 2.62 3.08 5.96 6.73 4.81 3.91 3.38 1.87 1.06 38.2
 
Fort Lupton Avg. Temp F 28.03 37.27 42.01 48.41 54.61 71.57 74.83 70.05 64.65 57.19 45 26.66 51.69
Ref date as of 12/31/2016 Total Precip " 0.54 0.72 0.83 2.99 3.12 2.39 0.79 0.84 0.13 0.43 0.3 0.51 13.59
Site Type: Turf Total Alfalfa ETr " 1.69 3.38 4.36 5.2 5.16 9.08 9.46 7.99 6.16 5.34 3.11 1.75 62.68
Total Growing Degee Days from March 1 0 0 135 200 280 604 689 607 485 385 199 23 3607
Gross Pond Evap Inch 1.42 2.84 3.66 4.37 4.33 7.63 7.95 6.71 5.17 4.49 2.61 1.47 52.65
Net Pond Evap Inch 1.04 2.34 3.08 2.28 2.15 5.95 7.39 6.12 5.08 4.18 2.4 1.11 43.12
 
Boulder NW Avg. Temp F 31.71 39.04 40.9 47.5 54.07 71.41 74.14 69.3 63.42 57.06 45.71 29.72 52
Ref date as of 12/31/2016 Total Precip " 0.32 0.54 2.33 3.01 1.82 0.77 0.68 0.84 0.55 0.36 0.36 0.6 12.18
Site Type: Turf Total Alfalfa ETr " 1.93 3.4 3.8 4.77 5.69 8.15 8.39 6.76 5.26 4.82 2.88 1.97 57.82
Total Growing Degee Days from March 1 0 0 111 182 265 593 681 576 449 366 188 43 3454
Gross Pond Evap Inch 1.62 2.86 3.19 4.01 4.78 6.85 7.05 5.68 4.42 4.05 2.42 1.65 48.58
Net Pond Evap Inch 1.4 2.48 1.56 1.9 3.51 6.31 6.57 5.09 4.03 3.8 2.17 1.23 40.05
 
Boulder East Avg. Temp F #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Ref date as of 5/2/2010 Total Precip " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Site Type: Turf Total Alfalfa ETr " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Total Growing Degee Days from March 1 0 0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Gross Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Net Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
 
Boulder Flatiron Avg. Temp F #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Ref date as of 5/2/2010 Total Precip " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Site Type: Turf Total Alfalfa ETr " #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Total Growing Degee Days from March 1 0 0 #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Gross Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
Net Pond Evap Inch #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A #N/A 0
 
Boulder SW Avg. Temp F 34.93 41.58 42.76 48.44 54.27 71.2 73.39 69.03 63.96 58.48 47.63 31.01 53.06
Ref date as of 12/31/2016 Total Precip " 0.17 0.48 2.13 2.96 1.93 1.86 0.6 0.95 0.47 0.46 0.4 0.58 12.99
Site Type: Turf Total Alfalfa ETr " 2.26 3.82 4.11 5.17 5.5 8.03 8.27 7.1 5.48 5.36 3.03 2.21 60.34
Total Growing Degee Days from March 1 0 0 98 160 241 599 653 571 436 336 165 38 3297
Gross Pond Evap Inch 1.9 3.21 3.45 4.34 4.62 6.75 6.95 5.96 4.6 4.5 2.55 1.86 50.69
Net Pond Evap Inch 1.78 2.87 1.96 2.27 3.27 5.44 6.53 5.3 4.27 4.18 2.27 1.45 41.59
Greeley04 Avg. Temp F 22.37 33.68 40.82 47.63 55.13 71.45 72.23 67.67 62.15 52.88 40.85 21.61 49.04
Ref date as of 12/3116/2016 Total Precip " 0.27 0.09 0.89 2.28 1.71 0.57 1.31 2.48 0.3 0.69 0.12 0.1 10.81
Site Type: Fully irrigated Total Alfalfa ETr " 1.31 3.27 5.12 5.57 6.72 9.42 8.97 7.34 5.59 4.7 3.48 0.69 62.18
Total Growing Degee Days from March 1 0 0 132 203 291 587 655 568 457 357 175 2 3427
Gross Pond Evap Inch 1.1 2.75 4.3 4.68 5.64 7.91 7.53 6.17 4.7 3.95 2.92 0.58 52.23
Net Pond Evap Inch 0.91 2.68 3.68 3.08 4.45 7.51 6.62 4.43 4.49 3.47 2.84 0.51 44.67